Topic 1

• Monomers are smaller units which can create larger molecules and the polymers are made from lots of monomers which are bonded together
• Examples of monomers


  • Glucose
  • Amino acids
  • Nucleotides
• Examples of polymers


  • Starch
  • Cellulose
  • Glycogen
  • Proteins
  • DNA
  • RNA
• Condensation reaction to create polymers


  1. Joining two molecules together

  2. Creating a chemical bond

  3. Removing water
• Hydrolysis reaction to break apart polymers

  1. Breaking a chemical bond between two molecules

  2. Involves the use of water
• Monosaccharides


  • Glucose
  • Fructose
  • Galactose
• Disaccharides


  • Sucrose
  • Maltose
  • Lactose
• Polysaccharides


  • Starch
  • Cellulose
  • Glycogen
• Alpha glucose


  Hydrogen atom on top, hydroxyl group on bottom of carbon 1
• Beta glucose


  Hydroxyl group on top, hydrogen atom on bottom of carbon 1
• Glycosidic bond


  Chemical bond that forms between two monosaccharides to create a disaccharide
• Maltose is made from glucose + glucose, lactose is made from glucose + galactose, sucrose is made from glucose + fructose
• Starch


  • Stored in plants as a source of glucose
  • Made from alpha glucose
• Cellulose


  • Structural component in plant cell walls
  • Made from beta glucose
• Glycogen


  • Stored in animals as a source of glucose
  • Made from alpha glucose
• Starch and glycogen have 1-4 and 1-6 glycosidic bonds, cellulose has only 1-4 glycosidic bonds</b>
• Amylose


  Unbranched polymer of starch with only 1-4 glycosidic bonds
• Amylopectin


  Branched polymer of starch with both 1-4 and 1-6 glycosidic bonds
• Polysaccharides are large and insoluble, so they don't affect water potential or osmosis
• Cellulose


  • Long straight chains held together by hydrogen bonds, providing structural strength
• Glycogen


  • Highly branched structure with more 1-6 glycosidic bonds than starch, allowing rapid hydrolysis to glucose
• Lipids


  • Triglycerides
  • Phospholipids
• Condensation reaction to form triglycerides

  3 fatty acids join to glycerol, 3 water molecules removed
• Ester bond


  Bond that forms between fatty acids and glycerol in triglycerides
• Saturated fatty acid


  No double bonds between carbon atoms, fully saturated with hydrogen
• Unsaturated fatty acid


  At least one double bond between carbon atoms
• Triglycerides


  • High ratio of energy-storing C-H bonds to C atoms
  • Can act as metabolic water source when oxidized
  • Do not affect water potential or osmosis
• Phospholipids


  • Hydrophilic head (phosphate group) and hydrophobic tails (fatty acids)
  • Can form a bilayer in water
• Amino acids


  • Central carbon
  • Hydrogen
  • R group
  • Amino group
  • Carboxyl group
• Condensation reaction to form a dipeptide


  Two amino acids join, water removed, peptide bond forms
• Condensation reactions to form a polypeptide


  Multiple amino acids join, multiple peptide bonds form
• Primary structure


  Order or sequence of amino acids in a polypeptide chain
• Secondary structure


  Folding or twisting of the polypeptide chain, held by hydrogen bonds
• Tertiary structure


  Further folding of the polypeptide chain, held by ionic, hydrogen and disulfide bonds
• Quaternary structure


  Protein made up of more than one polypeptide chain
• Enzymes


  • Proteins in tertiary structure that catalyze reactions
  • Have a specific active site complementary to a substrate
  • Use induced fit model - active site changes shape to bind substrate
• Enzymes lower the activation energy of reactions
• Active site


  Complementary in shape to a particular substrate
• Lock and key model

  Enzyme's active site is complementary in shape to the substrate
• Induced fit model


  Enzyme's active site slightly changes shape to mould around the substrate